Wood River times. [volume] (Hailey, Idaho) 1882-1915, 1887-11-14
THE COLONIZATION PROCESS
HOW 1T Is OPERATED A LEAD.
ING CALIFORNIA NINE.
The Free Gold Saved ON the Plates and
the Suiphnrets Toasted and Leached -
The Cost Per Ton,

FJ' "' S""h'y, Nai.S were
read at meeting Of the American
Institute of Mining Engineers by
George w. Small, +. NJ Oconomo.
woe, Wis:
The ore, as it is raised from the
nine, has an average assay value OF
sll per ton, chiefly in the form of free
gold. Al! the ore goes directly to the
stamp mills, Of which there are two.
The older and larger mill contains IL
batteries OF five stamps each, with one
Frue vanner to each battery. The
new mill has eight batteries OF
five stamps and two Frues to each
battery. The large mill is driven BY
Letfel turbine wheels, with pressure
of 80 feet, and consumption of 600
miners inches Of water. The smaller
mill is driven by Sturdy, gurdy" wheels
with pressure of about $50 feet aud
a consumption of $50 miners inches
of water.
At both mills the taiings from the
stamps pass over about 20 feet of
plates on their way to the Frues. In
each set OF plates the first or upper
one is copper; the rest are So called
silver plates.
The bullion from the stamps is
about 500 fine in gold and 200 in
silver.
THE CONCENTRATES
from the Frues average from II to II
per cent. of the ore stamped. They
very rarely exceed per cent. Twas
unable TO get the exact assay value OF
the concentrates, but it is said to
vary between 800 and 1900 per ton
The concentrates are treated at the
colonization works at the rate of 100
tons per month. The capacity of the
works is somewhat greater than this,
but az the supply OF concentrates is
limited, it is not deemed advisable 70
work them up any faster.
Care is taken to keep the concen.
trates always damp until they are put
into the roasting furnace. If this is
not done, a decomposition of the
pyiites begins, forming Jumps which
do not roast, and which consequent,
cause loss of gold in the residues
from teaching.
A Fortschaufelungsofen is used for
roasting. The hearth is one contin, .
Gus plane, but the charges, of which
there are three in the furnace at one
time, are kept entirely separate. The
furnace men call the three compart.
ments the drying" the "burning,'
and the cooking" compartments. In
the middle, or burning compartment,
the ore is spread out very thin, and
occupies double the space of the other
compartments.
THE FURNACE
is worked by e,ght-hour shifts, one
man on each shift, and one charge is
drawn and a new one added in each
shift. The charges weigh 240G lbs,
and carry about ten per cent. of
moisture. The Gre averages about 20
per cent. in sulphur, and just before
the sun ceases flaming (in the second
division of the furnace) 10 pounds, or
three. fourths per cent, of salt is added
to the charge.
The roasted ore from each shift is
kept by itself on the cooling. Aoo-
until tankfu! (about four ,ons) has
accumulated from single mans
shift; then that lot is worked by it.
self. This enables the person in
charge to better control the roasting,
for, if only one lot out of the thrt is
bad, it is presumable that the fault
lies with the workman; but if all
three are bad, the probabilities are
that there has been a material change
in the character Of the ore, and the
roasting process must be. altered &C
cordingiy.
the WATTS PoR cRLORIDIZING
the roasted ore are nine feet in diam
eter by three feet in hight, and are
four in number. They are slis htly
inclined, SO tina. they will drain, com.
pletely. The bottom Of each tank ia
occupied by filter abou. six incl. es
thick, composed as follows: Ligh,
strips of three-quarter-inch wood are
frs, laid in the bottom of the tank q,
intervals of ABOUT one foot. Across
these strips are laid six-inch boards
leaving cracks of an inch or more be
tween the boards. On top of ,hi.
Ioose floor are placed coarse Jumps Of
quartz, and on top Of this again finel
quartz material, until total depth o.
five or six inches is obtained. FINAL,
this "sandflter" is covered by an
other loose floor, the boards lying
crosswise to the loose floor beneath
and pretty close together. This upper
aoor is intended merely to furnish .
shoveling furnace, 30 as to permit the
removal Of the ieached ore from the
tanks without disturbing the filter.
The ore to be chloridized must b.
damp--about six per cent. moisture
The working test is, to take handful
of the ore and squeeze it, theu open
tho hand, and If the lump immedi.tel,
| beoips In erumkle and fall anart I'm,